1. Field of the Invention
The present invention relates to a printing system having a computer system for executing various application programs and a printer with a sleep mode, and more particularly to a printing system enabling an automatic wake-up operation of a printer to make a prompt printing operation by transmitting a wake-up command to the printer which is in the sleep mode when a printer driver is called through an operating system (OS) in preparation for a printing operation according to an application program.
2. Description of Related Art
Heretofore, for one of printers which print in accordance with the print data transmitted from a personal computer, there has been known a printer which enters a sleep mode by cutting off power supply to a part of a hard wear of the printer itself if it does not perform a printing operation for more than a preset time.
The sleep mode is an effective function for power saving in printers. Because it can prevent a toner fixing heater from being continuously heated while the printer does not perform printing for a long time, which would cause waste power consumption.
The printer with the sleep mode, generally, is arranged so that it is released from the sleep mode when the printer receives a signal representative of print data from, for example, a personal computer and then starts a warm-up process. If, however, the print data is transmitted from a personal computer to the printer during a sleep mode, the printer could start a printing operation after the elapse of a remarkably long time from the signal transmit time, so that it takes a long time to complete the printing operation.
To resolve the above problem, for instance, in Japanese Patent unexamined publication No. 7-210039, there is disclosed a power saving printing method of a printing system having a personal computer with an input device and an image forming device for performing a printing operation when the device receives a print code from the computer, wherein a power saving mode is established when the device does not carry out a print operation for a predetermined period of time. This method includes inputting a dummy print code from the computer to the image forming device when the specific input previously provided in the input device of the computer enters to the image forming device during the power saving mode, and performing a wake-up operation of the device when received the dummy print code to enter a standby mode.
According to the above power saving printing method, a wake-up operation can be performed by computer input prior to an actual printing operation, which makes it possible to reduce a time required to perform a wake-up operation of the device in the power saving mode in preparation for a printing operation.
However, this method needs the entry of the specific input through the input device of the computer in order to wake up, prior to a printing operation, the image forming apparatus during the power saving mode. Such entry of the specific input has to be executed by a user entering a specific code with a keyboard of the computer prior to a printing operation, but most of users often forget to enter the specific code in advance.
If a user had forgotten to enter the specific code in advance, the wake-up operation of the image forming device is performed at the time that a print code is input according to a print start command. In this case, a printing operation is executed after the long lapsed time from the time print data have been transmitted to the image forming device, resulting in a long printing time.